1. Field of the Invention
The invention concerns a process for a vehicle control and information system, where data and traffic-relevant information are transmitted between a vehicle and a central unit by means of at least one wireless transmission system.
2. Discussion of Prior Art
Various methods and arrangements for vehicle control and information systems have already become known. Two main types of systems can be identified in particular. The first are autarchic navigation systems, where navigation of the vehicle takes place in the navigation system itself. However, this requires that a considerable quantity of route information be loaded and stored on suitable data storage media. Further, access to prevailing current traffic information is impossible with such systems.
An autarchic map information system with navigation and route planning options is known from the company CARDY Karten Informations Systeme GmbH, Monchengladbach, and was presented in a brochure in October 1993. CARDY is a map information system with a navigation program based on an electronic map database available on a data storage medium in the vehicle. With the help of a GPS system, a so-called "MAP matching" is performed that is, the map detail is matched to the vehicle position thus determined, so that the current location of the vehicle can be displayed permanently on the corresponding map detail. The vehicle position determined by GPS can also be transmitted by wireless transmission to a central unit for the purpose of fleet management, for example. Route planning is also possible on the basis of the maps stored electronically in the vehicle, where the navigation of the vehicle is based on the planned route and the vehicle position is determined by the GPS system.
By the Traffic Message Channel (TMC) method in conjunction with the Radio Data Systems (RDS), coded traffic information is transmitted in addition to the current wireless program. In the vehicle, it is possible to select from the information available that which is of interest for the instantaneous region and direction of travel. In addition to the ongoing need for data processing in the vehicle, no specific, individually coordinated distribution of information is possible with such systems. This can be accomplished by establishing a connection between the vehicle and one or more central information units via bidirectional data transmission systems such as wireless transmission systems. A permanently installed beacon system, where a suitable vehicle device makes contact with a beacon on passing by it, is a way of effecting this result. To provide complete information however, this requires coverage of the area by a network of beacons, which is generally impossible to implement. The area supplied with information is therefore usually limited mainly to densely populated areas.
Furthermore, a bidirectional exchange of information can be achieved by using a wireless transmission system such as a digital GSM network and can be maintained continuously by total coverage through mobile wireless systems.
It is usually desirable to provide the driver only with the specific information concerning his instantaneous location on a certain section of the route and his direction of travel. The System Of Cellular Wireless for Traffic Efficiency and Safety (SOCRATES) is known for this purpose; it filters traffic information transmitted regionally over GSM on the basis of position information and route information available in the vehicle and displays it for the driver. However, this automatically leads to the need for positioning devices for continuous determination of the position of the vehicle, and this is associated with a corresponding cost and technical complexity.